Rethinking the cerebellum

It used to be so simple.  The cerebral cortex handled cognition, while the cerebelllum coordinated motor skills.  Recent work indicates that simplistic view presents a false dichotomy.

An ancient part of the brain long ignored by the scientific world appears to play a critical role in everything from language and emotions to daily planning...

Schmahmann, who wasn't involved in the new study, has been arguing for decades that the cerebellum plays a key role in many aspects of human behavior, as well as mental disorders such as schizophrenia...

And what they found was that just 20 percent of the cerebellum was dedicated to areas involved in physical motion, while 80 percent was dedicated to areas involved in functions such as abstract thinking, planning, emotion, memory and language...

The cerebellum doesn't directly carry out tasks like thinking, just as it doesn't directly control movement, Marek says. Instead, he says, it appears to monitor the brain areas that are doing the work and make them perform better.

In essence, this structure appears to act as a kind of editor, constantly reviewing and improving a person's thoughts and decisions, Dosenbach says. If that's true, he says, it's no surprise that alcohol affects more than our physical movements.

This is fascinating.   Read more at NPR, where there is a link to the source article.

Reposted from 2018 to add excerpts from an interesting recent Atlantic article:

Investigations of the cerebellum have exploded over the last few years, says Catherine Stoodley, a neuroscientist at American University and a coauthor of a 2019 paper in the Annual Review of Neuroscience on the cerebellum’s role in cognition. “It’s very exciting.”..

Leiner also questioned why the cerebellum evolved to be so much larger in humans than in other animals. (According to one estimate, the human cerebellum is, on average, 2.8 times bigger than expected in primates our size.) Why would that be so, if all it did was coordinate movement?...

In the late 1990s, Schmahmann reported the first description of cerebellar cognitive affective syndrome after observing that people with cerebellar damage—due to degeneration or after tumor removal, strokes, and infection—exhibited a wide array of impairments in cognition and behavior. These included difficulties with abstract reasoning and planning, changes in personality...

Given the cerebellum’s myriad roles, some scientists suspect the structure may be involved in several brain-related disorders. The two conditions for which there is currently the most evidence are autism and schizophrenia...

Note: cerebellum is the Latin diminutive of cerebrum, and thus translates as "little brain."